Dilemma: Use of genes in gestation

Dilemma: Use of genes in gestation
It is a prenatal genetic engineering project, seeking perfection with genes that provide beneficial results and eliminate all diseases and disabilities; introducing improvements to increase the quality of life, intelligence, good social habits. But, it will also be allowed that the parents who wish to, can eliminate some improvements and that the child grows up without genetic changes.
The result of these procedures means that some defects cannot be eliminated or corrected, which would cause potential babies to be eliminated.
Selecting and choosing among babies, is it a task that corresponds to God, to the parents, to the state?